Determination of p16 overexpression as an indicator of human papillomavirus infection in oral dysplasia and carcinoma

Abstract

Context: Oral and pharyngeal cancer, grouped together, is the sixth most common cancer in the world. In the past few years, human papillomavirus (HPV) infection has been suggested as a risk factor for oral cancer apart from traditional risk factors such as smoking, tobacco, and alcohol consumption. Aims: The aim of this study was to determine HPV status of the tumors using polymerase chain reaction (HPV-DNA PCR) and p16 immunostaining and to correlate p16 overexpression as an indicator of HPV-associated oral dysplasia and carcinoma. Settings and Design: A prospective study was conducted in fifty cases of suspected oral cancer. Materials and Methods: PCR Amplification of extracted HPV-DNA was done for HPV-DNA status in fresh tissue of suspected oral cancer cases. Histomorphological features of the cases were analyzed, and p16 immunohistochemistry was performed on the same specimen after making paraffin blocks to study p16 overexpression. Statistical Analysis Used: Chi-square test was used to analyze the differences between discrete variables. Results: 5/6 (83.3%) HPV-DNA-positive cases were positive for p16 expression, whereas 26/44 (59.09%) p16-positive cases which were negative for HPV-DNA. Sensitivity and specificity of p16 as a surrogate marker for HPV-DNA were found to be 83.3% and 40%, respectively. Conclusions: p16 immunostaining is a good first-line assay for eliminating HPV-negative cases from additional analysis, but other causes of p16 overexpression in oral tumorigenesis related to tobacco consumption in keratinizing squamous cell carcinoma needs to be explored further.

Keywords

• Head and neck squamous cell cancer
• human papillomavirus
• p16 immunohistochemistry
• polymerase chain reaction